315 research outputs found
Survival Differences among Native-Born and Foreign-Born Older Adults in the United States
Studies show that the U.S. foreign-born population has lower mortality than the native-born population before age 65. Until recently, the lack of data prohibited reliable comparisons of U.S. mortality by nativity at older ages. This study provides reliable estimates of U.S. foreign-born and native-born mortality at ages 65 and older at the end of the 20(th) century. Life expectancies of the U.S. foreign born are compared to other developed nations and the foreign-born contribution to total life expectancy (TLE) in the United States is assessed.Newly available data from Medicare Part B records linked with Social Security Administration files are used to estimate period life tables for nearly all U.S. adults aged 65 and older in 1995. Age-specific survival differences and life expectancies are examined in 1995 by sex, race, and place of birth.Foreign-born men and women had lower mortality at almost every age from 65 to 100 compared to native-born men and women. Survival differences by nativity were substantially greater for blacks than whites. Foreign-born blacks had the longest life expectancy of all population groups (18.73 [95% confidence interval {CI}, 18.15-19.30] years at age 65 for men and 22.76 [95% CI, 22.28-23.23] years at age 65 for women). The foreign-born population increased TLE in the United States at older ages, and by international comparison, the U.S. foreign born were among the longest-lived persons in the world.Survival estimates based on reliable Medicare data confirm that foreign-born adults have longer life expectancy at older ages than native-born adults in the United States
Inelastic light scattering and the excited states of many-electron quantum dots
A consistent calculation of resonant inelastic (Raman) scattering amplitudes
for relatively large quantum dots, which takes account of valence-band mixing,
discrete character of the spectrum in intermediate and final states, and
interference effects, is presented. Raman peaks in charge and spin channels are
compared with multipole strengths and with the density of energy levels in
final states. A qualitative comparison with the available experimental results
is given.Comment: 5 pages, accepted in J. Phys.: Condens. Matte
Raman scattering in a two-dimensional electron gas: Boltzmann equation approach
The inelastic light scattering in a 2-d electron gas is studied theoretically
using the Boltzmann equation techniques. Electron-hole excitations produce the
Raman spectrum essentially different from the one predicted for the 3-d case.
In the clean limit it has the form of a strong non-symmetric resonance due to
the square root singularity at the electron-hole frequency while
in the opposite dirty limit the usual Lorentzian shape of the cross section is
reestablished. The effects of electromagnetic field are considered
self-consistently and the contribution from collective plasmon modes is found.
It is shown that unlike 3-d metals where plasmon excitations are unobservable
(because of very large required transfered frequencies), the two-dimensional
electron system gives rise to a low-frequency ()
plasmon peak. A measurement of the width of this peak can provide data on the
magnitude of the electron scattering rate.Comment: 4 pages, 3 figures. to appear in Phys. Rev. B 59 (1999
First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe
We perform a first principles calculation of the anomalous Hall effect in
ferromagnetic bcc Fe. Our theory identifies an intrinsic contribution to the
anomalous Hall conductivity and relates it to the k-space Berry phase of
occupied Bloch states. The theory is able to account for both dc and
magneto-optical Hall conductivities with no adjustable parameters.Comment: 4 pages, 6 figures, author list correcte
Geodetic Strain Analysis Tool
A geodetic software analysis tool enables the user to analyze 2D crustal strain from geodetic ground motion, and create models of crustal deformation using a graphical interface. Users can use any geodetic measurements of ground motion and derive the 2D crustal strain interactively. This software also provides a forward-modeling tool that calculates a geodetic velocity and strain field for a given fault model, and lets the user compare the modeled strain field with the strain field obtained from the user s data. Users may change parameters on-the-fly and obtain a real-time recalculation of the resulting strain field. Four data products are computed: maximum shear, dilatation, shear angle, and principal components. The current view and data dependencies are processed first. The remaining data products and views are then computed in a round-robin fashion to anticipate view changes. When an analysis or display parameter is changed, the affected data products and views are invalidated and progressively re-displayed as available. This software is designed to facilitate the derivation of the strain fields from the GPS and strain meter data that sample it to facilitate the understanding of the strengths and weaknesses of the strain field derivation from continuous GPS (CGPS) and other geodetic data from a variety of tectonic settings, to converge on the "best practices" strain derivation strategy for the Solid Earth Science ESDR System (SESES) project given the CGPS station distribution in the western U.S., and to provide SESES users with a scientific and educational tool to explore the strain field on their own with user-defined parameters
Impact of free on-site vaccine and/or healthcare workers training on hepatitis B vaccination acceptability in high-risk subjects: a pre-post cluster randomized study
AbstractDespite recommendations for adults at high-risk of hepatitis B virus (HBV) infection, HBV vaccine uptake remains low in this population. A pre-post randomized cluster study was conducted to evaluate the impact of on-site free HBV vaccine availability and/or healthcare worker training on HBV vaccination acceptability in high-risk adults consulting in 12 free and anonymous HIV and hepatitis B/C testing centres (FATC). The FATC were randomly allocated into three groups receiving a different intervention: training on HBV epidemiology, risk factors and vaccination (Group A), free vaccination in the FATC (Group B), both interventions (Group C). The main outcomes were the increase in HBV vaccination acceptability (receipt of at least one dose of vaccine) and vaccine coverage (receipt of at least two doses of vaccine) after intervention. Respectively, 872 and 809 HBV-seronegative adults at high-risk for HBV infection were included in the pre- and post-intervention assessments. HBV vaccination acceptability increased from 14.0% to 75.6% (p <0.001) in Group B and from 17.1% to 85.8% (p <0.001) in Group C and HBV vaccine coverage increased from 9.4% to 48.8% (p <0.001) in Group B and from 11.2% to 41.0% (p <0.001) in Group C. The association of training and free on-site vaccine availability was more effective than free on-site vaccine availability alone to increase vaccination acceptability (ratio 1.14; from 1.02 to 1.26; p 0.017). No effect of training alone was observed. These results support the policy of making HBV vaccine available in health structures attended by high-risk individuals. Updating healthcare workers’ knowledge on HBV virus and its prevention brings an additional benefit to vaccination acceptability
Quasiparticle dynamics in ferromagnetic compounds of the Co-Fe and Ni-Fe systems
We report a theoretical study of the quasiparticle lifetime and the
quasiparticle mean free path caused by inelastic electron-electron scattering
in ferromagnetic compounds of the Co-Fe and Ni-Fe systems. The study is based
on spin-polarized calculations, which are performed within the
approximation for equiatomic and Co- and Ni-rich compounds, as well as for
their constituents. We mainly focus on the spin asymmetry of the quasiparticle
properties, which leads to the spin-filtering effect experimentally observed in
spin-dependent transport of hot electrons and holes in the systems under study.
By comparing with available experimental data on the attenuation length, we
estimate the contribution of the inelastic mean free path to the latter.Comment: 10 pages, 10 figure
First-Principles Dynamical Coherent-Potential Approximation Approach to the Ferromagnetism of Fe, Co, and Ni
Magnetic properties of Fe, Co, and Ni at finite temperatures have been
investigated on the basis of the first-principles dynamical CPA (Coherent
Potential Approximation) combined with the LDA (Local Density Approximation) +
Hamiltonian in the Tight-Binding Linear Muffintin Orbital (TB-LMTO)
representation. The Hamiltonian includes the transverse spin fluctuation terms.
Numerical calculations have been performed within the harmonic approximation
with 4th-order dynamical corrections. Calculated single-particle densities of
states in the ferromagnetic state indicate that the dynamical effects reduce
the exchange splitting, suppress the band width of the quasi-particle state,
and causes incoherent excitations corresponding the 6 eV satellites. Results of
the magnetization vs temperature curves, paramagnetic spin susceptibilities,
and the amplitudes of local moments are presented. Calculated Curie
temperatures () are reported to be 1930K for Fe, 2550K for Co, and
620K for Ni; for Fe and Co are overestimated by a factor of 1.8,
while in Ni agrees with the experimental result. Effective Bohr
magneton numbers calculated from the inverse susceptibilities are 3.0 (Fe), 3.0 (Co), and 1.6 (Ni), being in
agreement with the experimental ones. Overestimate of in Fe and Co
is attributed to the neglects of the higher-order dynamical effects as well as
the magnetic short range order.Comment: 10 pages, 13 figure
Anastrozole-related acute hepatitis with autoimmune features: a case report
<p>Abstract</p> <p>Background</p> <p>Two cases of acute hepatitis occurring during treatment with anastrozole have previously been reported, but the underlying mechanisms of liver injury are still uncertain. We report the case of anastrozole-related acute hepatitis with some autoimmune features.</p> <p>Case presentation</p> <p>A 70-year-old woman developed acute hepatitis associated with serum antinuclear antibodies during anastrozole treatment; after drug withdrawal, liver function parameters rapidly improved and serum auto-antibodies were no longer detectable.</p> <p>Conclusions</p> <p>Anastrozole-induced hepatotoxicity is a very rare event. Drug-drug interactions or metabolically-mediated damage might be involved, with a possible role of individual susceptibility. Our report suggests that an immune-mediated mechanism may also be considered in anastrozole-related liver injury.</p
- …